Project Summary/Abstract Heart failure (HF) is a major public health problem worldwide, and half of patients presenting with HF have preserved (HFpEF), rather than reduced ejection fraction. However, HFpEF remains a therapeutic challenge, given current limited understanding of causal and contributing factors, and clinical heterogeneity within HFpEF subphenotypes. The central goal of the candidate's research work is to use clinical and translational research approaches to better understand mechanisms and contributors to human HFpEF and its subphenotypes. One focus in the laboratory has been to study the role of obesity, which is thought to induce a systemic pro- inflammatory state that, in turn, drives cardiovascular dysfunction and remodeling leading to HFpEF. The candidate is a heart failure cardiologist with a research focus on HFpEF and a long-standing track record of successful mentoring. Current work includes a multi-cohort effort to examine upstream regulators of systemic inflammation in HFpEF. This is complemented by a prospective ongoing study examining the role of obesity and insulin-resistance in HFpEF-associated pulmonary hypertension. The overarching goals of this proposal are to provide the candidate with the crucial long-term support to enable the ongoing reduction from clinical and administrative commitments, and to expand training opportunities for mentees interested in clinical and translational patient-oriented heart failure research. This application will support the candidate in creating unique training opportunities by leveraging ongoing funded efforts to enable new patient-oriented studies led by mentees. In Aim 1, we will investigate sex differences in inflammatory profiles in HFpEF in order to better understand why men and women with HFpEF display distinct disease phenotypes. In Aim 2, we will examine obesity and metabolic dysfunction as determinants of right ventricular function, an important predictor of outcomes in HFpEF. These research opportunities within the candidate's multidisciplinary research program, coupled with a vibrant scientific community and extensive educational resources at Massachusetts General Hospital and Harvard University will create an unparalleled environment for trainees pursuing a career in patient-oriented research. Ultimately, we hope this proposal will support the development and mentoring of new clinical investigators in heart failure research, and lay the foundation for future investigations focused on disease prevention and optimal therapies in HFpEF.